Rigby Limited's machining department had 20 000 units in work in process on 1 March. These units were 40 per cent complete with respect to conversion. Direct materials are added at the beginning of the production process, while conversion costs are incurred uniformly throughout the process. An additional 40 000 units were started during March, and 10 000 units were in work in process on 31 March. The units in work in process on 31 March were 20 per cent complete with respect to conversion.

Costs incurred in the machining department for March were as follows:

Work in process 1 March Costs incurred during March Total Direct material $ 78 000 $252 000 $330 000 Conversion 23 200 132 800 156 000 $101 200 $384 800 $486 000